"What's the point?" is the usual response Karl Fice-Thomson gets when he suggests providing surfing lessons to inner-city schools. But secondary school PE departments where he's introduced the latest Californian craze – "street surfing" – as part of the Surf Anywhere project have been so blown away by its ability to get even the most inactive kids exercising that they're buying up boards by the dozen and introducing it into the curriculum.

With the sport – which is a combination of snowboarding, skateboarding and surfing – also appearing to improve poor behaviour and having a particularly positive impact on children on the autistic spectrum, these PE teachers are having no trouble persuading school heads.

"I was sceptical at first," admits Denise Howard, director of sport at Brookfield school in Derbyshire. "But it's something completely different, and being in the middle of landlocked Derbyshire, the chance for students to have a go at any kind of surfing was too intriguing to turn down. I was amazed at what I saw. Children who hate PE had to be practically prised off the boards, and the confidence they gained from being able to do it well seems to be spilling over into their other work."

The impact that sport can have on young people's overall behaviour is hugely underestimated, believes Howard. "For many students, sport carries lots of negatives. It's often competitive and even if it's not, you wind up comparing yourself to others. That's fine if you're good, but not much fun if you're not."

Add to this the fact that sport often involves high expectations, and if you get something wrong, you're made to feel you've let the whole team down. Watch any bunch of kids playing football or netball and you'll always find a few who nobody passes the ball to. This has a spiral effect, since the more they are left out, the less chance they have of improving. Little wonder their self-esteem and, ultimately, their overall conduct is affected, says Howard.

For these kids, street surfing must feel as if it's been sent from heaven. For starters, it's cool, and better still, anyone can do it, even those with poor hand-eye coordination. Indeed, six million children worldwide have now been taught how to street surf, with 250,000 taught in the UK alone. "When you're the last kid picked for sports teams, it's horrid. I know because I was one of those kids. With street surfing, everyone's rubbish at first, but you suddenly get it and it's addictive," reports Fice-Thomson, who adds that the sport is increasingly used in training top snowboarders and surfers.

Fifteen-year-old Sam Greatorex agrees. "I skateboard, but this was something completely new. Some of us hadn't even heard of it. My first go was a bit wobbly and I was all over the place, but then I just got it," says Sam, who is among several children from each school that Surf Anywhere is funding to try out surfing this Easter in the Cornish sea. "There's a lot of self-expression involved. It's not about copying other people's moves and you don't compete against anyone else but yourself. It does make you feel good."

UK surfing champion Tassy Swallows agrees that surfing, whether on land or in the sea, is highly creative – something she believes may account for its appeal to those on the autistic spectrum. "Clay Marzo, who is one of the best surfers in the world, has Asperger's," says Swallows, also a member of the Surf Anywhere project. "I think it's something to do with being able to create your own style, coupled with the fact that you have the chance to forget about everything and everyone else around you."

In the US, surfing has long been recognised as benefiting autistic children. "It baffles everyone why it should work, but over the last few years we've noticed significant behavioural improvements," says Chris Brown, who teaches autistic children to surf in the UK. "Autistic children often experience sensory overload and anything out of the norm tends to throw them off, but surfing – whether in the sea or on land – seems to throw that theory on its head. We are currently working with Plymouth University to study why this might be the case and we hope the Surf Anywhere project may help to provide evidence. I've noticed similar effects with kids with behavioural problems. We've even managed to get kids who have been excluded back in school."

There's certainly something to be said for the healthy body, healthy mind theory, adds Fice-Thomson. "The physical benefits of street surfing are undisputed. Because the wave board has two wheels and can physically twist in the middle, you get the motion of surfing, which teaches core stability, as well as working core muscle groups. There's no doubt it's physically demanding, and with fitness comes confidence, acceptance from peers and an increased likelihood of being able to play a game of football with friends or go for a run."

Fice-Thomson admits that the only reason they started the Surf Anywhere project was because 60% of top British surfers are from inner cities. "We set out to find more of them, but we quickly saw that children ranging from the extremely overweight to the really reclusive ones took to street surfing as a sport in its own right, and it has in fact become the fastest-growing board sport around. Teachers often warn me, 'Well, it all sounds great, but I promise you that you won't get X doing it. He's never willingly put on a PE kit in his life.' But out of all the kids we've taught, only one didn't like it."

Jo Doyle, assistant head and director of PE at Cumberland school in Newham, east London, says many of her students went out to buy their own boards immediately. "I'd love to get a set here, too. After all, if you asked any student in this school what was their most memorable moment in PE, I guarantee you it would be the day they were introduced to street surfing – more so than any netball or other sporting event."